Strip-like fastener members comprising a great multiplicity of closely-spaced upstanding hook-like projections are used in many different applications for providing both releasable and semi-permanent connection of associated elements. These types of multi-hook fasteners are typically configured for coaction with a multi-loop or likewise "piled" element, with the multiple hooks engaging the closely-spaced multiple loops to provide the desired connecting or gripping action.
Depending upon the configuration of the multi-hook fastener member, many different types of materials and fabrics are adapted for coaction therewith to effect joining of the associated structures. Not only do such fastening devices have many applications for wearing apparel, recreational equipment, covers for cars and boats, and the like, such devices are further being advantageously employed in applications wherein the highly convenient connecting action promotes joining of associated structures in an essentially permanent manner. For example, such fastening devices are finding ever-increasing use in the automotive industry for efficient fabrication and assembly of components such as seats, interior trim, and the like.
Because the multi-hook fastener element of such fastening devices is often most advantageously and efficiently handled and used in an elongated, continuous strip form, various techniques have been developed for manufacture of such multi-hook fasteners in continuous strips. However, the difficulties associated with forming the large number of relatively small hook-like projections required for the desired fastening action has heretofore led those skilled in the art to resort to relatively complex forming devices and/or processes.
By way of example, U.S. Pat. No. 3,147,528, to Erb, discloses an openable injection mold having a large number of projection-forming cavities which open upwardly to a generally flat surface at the top of the mold. The cavities are defined by a series of separable mold plates. In use, a piece of fabric is positioned atop of the mold plates, and moldable material forced through the fabric so that it enters the cavities of the mold, thus forming a multi-hook fastener member. Since the mold itself is of a discrete length, formation of a continuous strip-like fastener member calls for relatively inefficient sequential or stepwise formation of individual segments of the member in end-to-end relation.
U.S. Pat. No. 3,758,657, to Menzin et al, discloses an apparatus for producing a continuous multi-hook fastener member. The apparatus includes a drum-like apparatus which includes a relatively complex arrangement of shiftable plates at its periphery which define cavities for forming hook-like projections. A plastic extruder is provided in close association with the drum so that as the drum rotates, plastic is injected into the hook-shaped cavities and is joined to a backing strip. Removal of the fastener member thus formed is accomplished by inwardly shifting alternate ones of the cavity-defining plates so that the cavities are opened to permit removal of the hook-like projections.
As will be appreciated, the above forming techniques require relatively complex equipment, and overall efficiency suffers due to the required opening of the hook-forming cavities to permit removal of the hook projections therefrom without damage or unacceptable deformation. The present method of forming a multi-hook fastener member affords a substantial improvement in the efficiency with which such members can be formed by permitting continuous formation of such a strip-like fastener member without unduly complex forming machinery.